A conventional device for confirming shift operation of a movable core of electromagnetic actuator has commonly employed an electric point mechanically connected to a movable core of the actuator. However, such conventional device has essentially provided following demerits or problems.
(1) Mechanism for connecting between the electromagnetic actuator and the electric point is complicated.
(2) The electric contact point has inherent demerits; that is, treatments for water proof, dust proof, moisture proof are complicated, and a lifetime of this electric contact point on account of influence of contact repetition should be considered.
(3) Switching operation of this electric contact point is checked through an electric signal, so that an extra power source and an electric wire for transmitting such signal are additionally required.
(4) The above mentioned problems make the manufacturing cost of this electromagnetic actuator increase.